Test laboratories need to monitor several hundred (up to several thousand) strain gages and other test devices during structural qualification of aircraft, launch vehicles, or other types of structures. A data acquisition system is commonly used to collect and collate test data. To ensure proper data collection, the connection between each strain gage or device and the data acquisition system needs to be verified. This end-to-end verification requires significant amounts of schedule time and labor during the test critical path. The verification typically involves reading labels on strain gage cables, de-mating or shorting connectors, or shorting strain gages and observing information in the data acquisition system.
The disadvantage of individually reading labels on cables, de-mating or shorting connectors, or shorting strain gages to determine proper connections for the strain gages is amplified when many thousands of strain gages are used. Modern aircraft installations can require up to approximately 8,000 strain gages for structural testing. The time and labor to change out individual cables for specific individual tests requires verification of the connection at both the strain gage end and data acquisition end of the individual cable channels. Where selected quantities of the strain gages are required for individual tests, each channel (i.e. strain gage to data acquisition system connection) is typically shorted at one end of the cable and verified by an operator at the opposite end of the cable. Large amounts of test time as well as delays in construction and delivery schedule can result from the verification process for each of the channels required for an individual test.
It is therefore desirable to provide a system which can be remotely controlled, which can automatically identify individual strain gages or devices for an individual test, and which eliminates the need for testing each channel for continuity prior to a test.